Choose between ExecutorService's submit and ExecutorService's execute

How should I choose between ExecutorService's submit or execute, if the returned value is not my concern?

If I test both, I didn't see any differences among the two except the returned value.

ExecutorService threadExecutor = Executors.newSingleThreadExecutor();
threadExecutor.execute(new Task());

ExecutorService threadExecutor = Executors.newSingleThreadExecutor();
threadExecutor.submit(new Task());